Science Scene - Battery Quest :o)

In a gleaming white factory here, sheets of chemical-coated foil are gently fed into a whirring machine that cuts them into precise rectangles. It is an early step in building a new kind of battery, one smaller than a cereal box but with almost as much energy as the kind in a conventional automobile.

The goal International Battery, a high-tech start-up, is industrial revolution. Racing against other companies around the globe, they are on the front lines of an effort to build smaller, lighter, more powerful batteries that could help transform the American energy economy by replacing gasoline in cars and making windmills and solar cells easier to integrate into the power grid.

The batteries would not only replace the fuel tanks in millions of cars and trucks, but would also make windmills and solar cells more practical, by absorbing excess energy when their production jumps and giving it back when the wind suddenly dies or the sun goes behind a cloud.

But first, companies like International Battery will have to tweak the chemistry of their devices and improve the manufacturing process, bolstering the batteries’ capabilities. And prices will have to come down — a problem that is far more daunting when it comes to batteries for vehicles and the grid, because the packs are hundreds or thousands of times the size of those for handheld electronics.

Nearly all battery research now focuses on lithium ion batteries, which made their consumer debut in 1991 and have since replaced nickel-cadmium and nickel-metal-hydride technologies in many portable electronics. Lithium is the third-lightest element on the periodic table, which allows for far greater energy density. A lithium ion battery that will move a car one mile weighs less than half as much as a nickel metal hydride and one-sixth as much as lead acid.

The engineers face a difficult challenge. The batteries have to store a lot of energy in a small, light package, scoring high in a quality known as energy density. They also have to absorb energy and give it back quickly, a factor called power density. Think of a battery as a bottle for energy, and the power density as the size of the bottle’s neck. Good power density means a shape like a peanut butter jar, easy to fill or empty; low power density is more like a wine jug with a narrow neck.

The batteries have to charge quickly and withstand thousands of cycles of charge and discharge. They have to dissipate heat without catching fire. The batteries must function in Maine winters and Texas summers. Engineers have met almost all of these goals, but not simultaneously in one product. And they are still way off on price: the components remain far too costly. But they are trying, devoting more and more resources to meeting that goal.

In 1991 the Advanced Battery Consortium was founded and set a near-term target for developing a battery that would cost $150 per kilowatt-hour of storage. (A kilowatt-hour sells for about a dime and will move a car three or four miles.) Eighteen years later, prices are in the range of $750 to $1,000. By comparison, a lead-acid battery in a conventional car costs less than $100 for that much capacity, although it is much too heavy to build an electric car around and not durable enough.

Now the Energy Department has a new goal: $500 by 2012. One reason for the optimism is the infusion of money that Washington is preparing to get the job done. The $2 billion in new grants planned this summer includes $1.2 billion for companies manufacturing battery cells and complete battery packs, $350 million for electric drive component manufacturing and $25 million for battery recycling.

The Obama administration is also hoping to drum up market demand. In March, President Obama, visiting a testing center for electric vehicles run by Southern California Edison in Pomona, announced tax credits of up to $7,500 for consumers who buy plug-in hybrid vehicles. Such models get some of their energy from the power grid and some from gasoline. But when it comes to a genuine mass market for an affordable plug-in hybrid or all-battery car, “we don’t quite know how to get there,” said Mr. Miller, of Ford.

The mastery of battery technology is key and we still have a lot of work to do.

Source: The New York Times/ Matthew Wald